Not applicable.
1. Field of the Invention
The subject invention relates to building components and, more particularly, to floor joists and floor systems fabricated from metal.
2. Description of the Invention Background
Traditionally, the material of choice for new residential and commercial building framing construction has been wood. However, over the years, the rising costs of lumber and labor required to install wood framing components have placed the dream of owning a newly constructed home out of the economic reach of many families. Likewise such increasing costs have contributed to the slowing of the development and advancement of urban renewal plans in many cities. Other problems such as the susceptibility to fire and insect damage, rotting, etc. are commonly associated with wood building products. Additional problems specifically associated with wooden floor joists include cost, availability and quality. These problems are particularly acute with respect to larger joists which must be harvested from large old growth forests which are becoming depleted.
In recent years, in an effort to address such problems, various alternative building materials and construction methods have been developed. For example, a variety of metal stud and frame arrangements have been developed for use in residential and/or commercial structures. U.S. Pat. No. 3,845,601 to Kostecky discloses such a metal wall framing system. While such system purports to reduce assembly costs and the need for welding or separate fasteners, several different parts are, nonetheless, required to complete the wall frame system which can be time consuming and expensive to inventory and assemble.
Such components must also be manufactured to relatively close tolerances to ensure that they will fit together properly thereby leading to increased manufacturing costs. Other metal stud systems for fabricating walls are disclosed in U.S. Pat. No. 3,908,328 to Nelsson, U.S. Pat. No. 4,078,347 to Eastman et al., U.S. Pat. No. 4,918,899 to Karytinos, U.S. Pat. No. 5,394,665 to Johnson, and U.S. Pat. No. 5,412,919 to Pellock et al. Such patents are particularly directed to wall system constructions and do not address various problems commonly encountered when installing floor and/or ceiling joists and support structures therefor within a building.
Conventional floor construction methods typically comprise installing xe2x80x9cheaderxe2x80x9d members on the top of support walls that may be fabricated from, for example, concrete blocks, wood or metal studs. The header members typically comprise wood beams that are supported on edge on the wall. Other wood beam members, commonly referred to as joists, are used to span from wall to wall between the headers and are usually connected to the headers by nails. The joists are typically arranged parallel to each other with 8xe2x80x3, 16xe2x80x3 or 24xe2x80x3 between their respective centers, depending upon the load characteristics that the floor must accommodate. A sheathing material such as plywood is then nailed to the upper edges of the joists to form the floor surface. To prevent the joists from inadvertently twisting or moving laterally, small pieces of wood, known as blocking pieces, are commonly nailed between adjacent joists to form, in many instances, X-shaped braces between the joists. Insulation is sometimes installed between the joists and sheathing, drywall, plasterboard, etc. is then applied to the bottom of the joists to form a ceiling for the space located under the floor joist system.
While these materials and floor construction arrangements have been used for many years in residential and commercial construction applications, they have many shortcomings that can contribute to added labor and material costs. For example, when connecting the joists to their respective headers, the carpenter must first measure and mark the headers to establish the desired joist spacing. This additional step increases the amount of construction time required to install the floor system and, thus, results in increased construction costs. After the headers are installed, the joists must be properly nailed to the headers. If the carpenter has access to the opposite side of the header from which the joist is to be installed, the nails are hammered through the header into the end of the respective joist. If, however, the carpenter cannot access the opposite side of the header, nails must be inserted at an angle (commonly referred to as xe2x80x9ctoenailingxe2x80x9d) through the joist and into the header. Care must be taken to avoid inadvertently splitting the joist and to ensure that the nails extend through the joist and into the header a sufficient distance. Such attachment process can be time consuming and may require the use of skilled labor which can also lead to increase construction costs. If toenailing is not structurally acceptable, another piece, called a joist hanger must be added which also increases labor and material costs.
It is also often desirable to install ductwork, piping, electrical wires, etc. within the floor joist system so that they do not occupy living space and are concealed by the ceiling material that is attached to the bottom of the joists. To accommodate those elements that must span multiple joists, passageways and/or holes must be provided through the joists. The number, size, and location of such passageways/holes must be carefully considered to avoid compromising the structural integrity of the joists. Furthermore, the blocking members may have to be moved or eliminated in certain instances to permit the ductwork and/piping to pass between the joists. In addition, cutting such passageways/holes into the joists at the construction site is time consuming and leads to increased labor costs. Another shortcoming associated with such floor joist systems is the difficulty of installing insulation between the joists due to the blocking members.
As noted above, there are many shortcomings associated with the use of wood floor joists and headers. In an effort to address some of the-above-noted disadvantages, metal beams have been developed. For example, U.S. Pat. No. 4,793,113 to Bodnar discloses a metal stud for use in a wall. U.S. Pat. No. 4,866,899 to Houser discloses a metal stud that is used to support wallboard panels,for forming a fire-rated wall and is not well-suited for supporting structural loads. U.S. Pat. No. 5,527,625 to Bodnar discloses a roll formed metal member with reinforcement indentations which purport to provide thermal advantages. The studs and metal members disclosed in those patents, however, fail to address many of the above-noted shortcomings and can be time consuming to install. Furthermore, many of the metal beams, studs, etc. disclosed in the above-mentioned patents typically must be cut in the field using hand tools. Such cuts often result in sharp, ragged edges which can lead to premature failure of the component when it is placed under a load.
In an apparent effort to better facilitate installation of various beams, U.S. Pat. No. 3,688,828 to Nicholas et al. discloses the use of L-shaped brackets to facilitate attachment of eaves boards and rafters to a C-shaped channel. While such arrangement may reduce assembly costs at the construction site, such brackets must be welded or separately affixed to the C-shaped channel which is time consuming and leads to increased manufacturing and fabrication costs. Furthermore, significant skill is typically required to properly layout and align the brackets.
Currently, metal floor joist material is generally cost-competitive with wood material. However, the nuances of assembling existing metal joists generally make them non-competitive when compared with wood joist arrangements.
Thus, there is a need for a floor joist that is relatively inexpensive to manufacture and install. There is a further need for a floor joist that can permit the passage of ductwork, piping, electrical wires, etc. therethrough without compromising the structural integrity of the joist and without encountering the on-site labor costs associated with cutting openings in the wood joists.
There is still another need for a joist support system that can be easily installed without the need for skilled labor.
Another need exists for a joist header that has a plurality of joist attachment locations pre-established thereon thus eliminating the need for the installers to layout each header.
Yet another need exists for a joist header that is relatively lightweight and that can be used to support metal or wooden joists in predetermined locations.
Another need exists for a joist header that has openings provided therein which can accommodate the passage of piping and/or wiring therethrough.
Still another need exists for a joist blocking member that can be attached between joists that is easy to install and can facilitate easy installation of insulation between joists.
A further need exists for a joist system that can, in some applications, eliminate the need for headers in support walls at window and door locations.
A need also exists for a joist support system that has the above-mentioned attributes that is easy to install and eliminates or reduces the amount of on-site cutting commonly associated with prior wood and metal joist components.
Yet another need exists for a floor joist system that eliminates the need to use a double 2xe2x80x3xc3x974xe2x80x3 wooden top plate to effectively distribute the load from the joists to the wall studs.
Still another need exists for a floor support system that can be easily used on connection with support structures of like and dissimilar constructions.
In accordance with a particularly preferred form of the present invention, there is provided a joist support apparatus that comprises a rim member that has a web portion and at least one attachment tab integrally formed in the web portion for attachment to a joist.
The subject invention may also comprise a member for supporting at least one joist member. The member may include a C-shaped rim member that is fabricated from metal and has a web and two leg portions. In addition, a plurality of joist attachment tabs are integrally formed in the web wherein the joist attachment tabs are provided at predetermined distances on the web relative to each other. At least one reinforcing rib corresponding to each tab is provided in the web adjacent the corresponding tab. The hole provided in the web when the tab is formed provides a convenient opening for passing pipes, wires, etc. through the rim member.
Another embodiment of the subject invention comprises apparatus for laterally supporting two joists. The apparatus may comprise a metal blocking member that has a body portion that is sized to extend between the two joists. The body portion may also have two opposing end tabs that are integral with the body portion and are substantially coplanar therewith. Each end tab corresponds to one of the joists for attachment thereto.
The subject invention may include a floor joist system that includes at least two joists that each have two ends and at least two joist rims that each have an attachment tab integrally formed therein that corresponds to one of the ends of the joists for attachment thereto.
Another embodiment of the present invention may include at least two metal joists that are substantially C-shaped such that each joist has a central web portion and an upper and lower leg portion protruding from the central web portion. Each central web portion has at least one opening therethrough that has a circumference and a reinforcing lip that extends around the circumference. The subject invention may also include at least one metal joist rim that is substantially C-shaped and has a rim web and an upper and lower rim leg protruding therefrom. The rim web is sized such that the end of a corresponding metal joist can be abutted substantially perpendicularly to the rim web of the corresponding joist rim and be received between the upper and lower rim legs thereof. The rim web of each joist rim further has at least one attachment tab integrally formed therein corresponding to each end of each corresponding joist. The attachment tab is substantially parallel to the corresponding joist end for attachment thereto. The rim web further has at least one reinforcing rib therein adjacent to each tab. The subject invention may further include at least one blocking member that has a body portion sized to extend between two joists. The blocking member has a body portion and two opposing end tabs integral with the body portion wherein each end tab corresponds to one of the joists for attachment thereto.
The subject invention may also comprise a method for constructing a floor between two spaced-apart support structures. The method may include supporting a joist rim on each support structure wherein the joist rim has a plurality of attachment tabs integrally formed therein. The joist rims are supported on said spaced-apart support structures such that the attachment tabs of one joist rim are substantially aligned with corresponding attachment tabs on the other joist rim. The method may also include attaching a joist corresponding to each pair of aligned attachment tabs such that the joists extend between the joist rims and are attached thereto. Each joist has a top surface such that when the joists extend between the joist rims and are attached to the aligned attachment tabs, the top surfaces of the joists are substantially coplanar with each other. The method may also include attaching a blocking member between adjacent joists to provide lateral support thereto and attaching sheathing to the coplanar top surfaces of the joists.
It is a feature of the present invention to a provide a floor joist that is relatively inexpensive to manufacture and install.
It is another feature of the present invention to provide a floor joist that can permit the passage of ductwork, piping, electrical wires, etc. therethrough without compromising the structural integrity of the joist and without encountering the on-site labor costs associated with cutting openings in the joists.
Another feature of the present invention involves the provision of a joist support system that can be easily installed without the need for skilled labor.
Yet another feature of the present invention is to provide a joist rim that reduces or eliminates the need for conventional web stiffeners.
Another feature of the present invention is to provide a joist rim that facilities easy passage of wires, pipes, etc. therethrough without the need to cut holes in the rim in the field and without compromising the structural integrity of the rim.
Still another feature of the present invention is to provide a floor joist support system that does not require the installation of a variety of different fastener parts that are commonly associated with prior metal beam and stud installations.
Another feature of the present invention is to provide a floor joist rim that can effectively distribute loads that, in the past, typically had to be accommodated by using double wood plates and the like.
It is another feature of the present invention to provide a joist header or rim that has a plurality of joist attachment locations pre-established thereon thus eliminating the need for the installers to layout each header.
Still another feature of the subject invention is to provide a pre-formed joist rim or header that is relatively lightweight and that can be used to support metal or wooden joists in predetermined locations.
It is another feature of the present invention to provide a pre-formed joist blocking member that is easy to install and that can facilitate easy installation of insulation between joists.
An additional feature of the subject invention is to provide a floor system that can, in some applications, eliminate the need for headers in support walls at window and door locations.
Still another feature of the present invention is to provide a joist support system that has the above-mentioned attributes and that is, easy to install and eliminates or reduces the amount of on-site cutting and measuring commonly associated with prior wood and metal joist components.
Yet another feature of the present invention is to provide a floor system that can be successfully used in connection with support structures of dissimilar construction.
Accordingly, the present invention provides solutions to the shortcomings of prior building components and floor systems. Those of ordinary skill in the art will readily appreciate, however, that these and other details, features and advantages will become further apparent as the following detailed description of the preferred embodiments proceeds.